The SYSTEM-500
consists of Eurorack format modules that you can mix and match in any
combination to create the ultimate Roland modular synthesizer. Each
module is completely analog and has been designed for maximum
compatibility with the world of contemporary synthesizer and effects
modules. The SYSTEM-500 is a compact, powerful system that opens up
vast possibilities for sound design and musical exploration.

530 Dual VCA

The 530 Dual VCA
(voltage controlled Amplifier) features two independent voltage
controlled amplifiers for controlling the loudness of audio signals.
Each VCA has three sliders for an audio input mixer, three sliders to
mix CV inputs, and a selector switch for linear or exponential
response modes.